A method for warning a driver of a vehicle is described in German Patent Application No. DE 100 39 795 A1, where a critical situation is detected by vehicle sensors and the attentiveness of the driver is determined. A warning of the critical situation is issued as a function of the driver's attentiveness. This allows the driver to be warned in case of low attentiveness, whereas when he/she is highly attentive, he/she does not receive any warnings of dangers he/she has already perceived.